1. Technical Field
This invention relates generally to fluid transfer devices and, more particularly, to panel assemblies for diverting fluids from one location to another.
2. Background of the Invention
Flow transfer panels are an important part of most processes and clean-in-place (CIP) systems in the food, beverage, dairy, pharmaceutical, and biopharmaceutical industries. The flow transfer panel provides the "physical break" required by most processing regulations and current Good Manufacturing Practices (cGMP's). In addition, flow transfer panels may be utilized for fluid diversion and delivery in industries where sanitary conditions and the inherent "physical break" are not process requirements.
As shown in FIG. 1, a typical transfer panel 10 generally includes a vertically oriented panel 12 and nozzles 14 that extend through the panel and are welded or otherwise attached thereto. Each nozzle includes a ferrule 16 formed at the end of a tube 18 and a mounting ring 19 formed on the tube and spaced from the ferrule 18. A jumper conduit 20 has a ferrule 22 connected at the ends of a U-shaped tube 24. The ferrules 22 of the jumper conduit 20 include faces 25 that mate with faces 26 of the ferrules 16. The ferrules 22 are connected to the ferrules 16 through clamps or the like to thereby direct the flow of fluid from one pipe to another.
The flow transfer panel 10 may be mounted on a floor, wall, or ceiling through appropriate supports and/or brackets, and provides a basic support structure for several nozzles and jumper conduits that may extend between one or more pairs of nozzles. Generally, flow transfer panels provide a physical break required by some processing regulations and assure that products will not be cross contaminated with other products or with CIP solutions that are used for cleaning the interior of conduits or pipes associated with fluid processing.
Assembly of the nozzles to the transfer panel typically involves forming openings in the panel 12 then inserting the tube 18 of each nozzle in one of the openings such that the ferrule 16 is located on one side 24 of the panel with the tube 18 extending through the panel. The nozzle 14 is then affixed to the panel by welding the outer perimeter of the ring 19 to the panel 12. With this arrangement, the distance between the panel and an outer face 26 of the ferrule 16 of each nozzle must be referenced from the side 24 of the panel, since the ring 19 is spaced at a fixed distance from the ferrule 16. Ideally, the outer faces 26 of the ferrules 16 should lie in a common plane 28. Although care is taken to provide a flat panel 12, dips 30 and bows 32 in the panel may occur during formation of the panel itself, and may be further augmented by subsequent manufacturing processes, such as stamping, forming openings in the panel, welding of the nozzles to the panel, and the like. It has been observed that for a 0.25 inch thick plate, the dips and bows may vary by as much as 0.25 inch or more over the area of the plate, which in some applications may be quite large. Consequently, the outer faces 26 of the ferrules do not lie along a common plane 28. When a jumper conduit 20 is connected to the ferrules under these circumstances, a gap "A" between a first pair of opposing faces 25 and 26 may be greater than a gap "B" between a second pair of opposing faces of ferrules 16 and 22. When the jumper conduit is installed on the nozzles 14, the gap "B" is closed, while the gap "A" may still be present. Consequently, leakage may occur at the junction of the ferrules 16 and 22 and contaminants may enter the processing line. In some cases, undue internal stresses may be created in the jumper conduit during an attempt to close gap "A" when assembling the jumper conduit to the nozzles. In many instances custom jumper conduits must be constructed, typically at the assembly sight away from the manufacturer, to accommodate the dips, bows and other deformities of the transfer panel, resulting in increased manufacturing and installation time, labor, and expense.
The above-described problems are further augmented by surface defects that may be present on the inner surface of the tube 18 during manufacture or during assembly to the panel 12. In many cases, the surface defects are not readily observable or cannot be measured until after an electro-polishing operation wherein the inner surface of the nozzle 14 is given a smooth, mirror-like finish. Even when the surface contains no visible or discernible defects before electro-polishing, the electro-polishing operation itself may uncover pits in the surface. This is especially prevalent where the surface is mechanically finished before electro-polishing. Mechanical finishing often fills pits and other defects in the surface due to welding or other manufacturing operations. Since a layer of material is removed from the surface during electro-polishing, some of the pits and other defects may be uncovered. In many manufacturing environments, the electro-polishing operation itself is inherently non-repetitive, since factors such as electrolyte concentration, temperature, and immersion time of the surface in the electrolyte may vary. Discontinuities in the finish can encourage contamination and bacteria growth and therefore are unacceptable in sterile processing environments. When surface defects are detected after the nozzle is installed in the panel, the nozzle must either be ground out, which is a labor-intensive and time-consuming procedure, or the panel must be discarded.
In an attempt to overcome surface defects in the nozzle that may be caused from welding the nozzle directly to the panel assembly, U.S. Pat. No. 5,603,457 issued to Sidmore et al. on Feb. 18, 1997, proposes forming a ring on the nozzle and an enlarged opening in the panel for receiving the ring. Me outer periphery of the ring is then welded to the panel and the welding bead is subsequently removed during a grinding operation. Although the ring effectively relocates the welding operation to a location spaced from the nozzle, the ring is the same thickness as the panel. The distance from the panel to a connection end of the nozzle must therefore be referenced from the panel itself Consequently, the connection ends of nozzles on the panel may not lie in the same plane due to dips, bows and other imperfections in the panel.